The ACA Chief Executive believes that the changes will create greater context around international cricket, however requires more work to ensure the public understands how the competitions will work.
"The Test Championship is something that has been talked about for a while, so i think that it is now important that has been formalised," Nicholson said.
"I think there is still work to do in regards to how it actually operates in regards to the weightings between the different series.
"But overall, we are cautiously optimistic on how it will go, and i know the players have been wanted further context around tests, so that's the main thing."
For the full list and explanation of the ICC changes, please click here.